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J/AJ/155/181        LAMOST/SP_Ace DR1 catalog                (Boeche+, 2018)

LAMOST DR1: stellar parameters and chemical abundances with SP_Ace. Boeche C., Smith M.C., Grebel E.K., Zhong J., Hou J.L., Chen L., Stello D. <Astron. J. 155, 181 (2018)> =2018AJ....155..181B (SIMBAD/NED BibCode)
ADC_Keywords: Galaxy catalogs ; Spectroscopy ; Abundances ; Stars, normal Keywords: catalogs - stars: abundances - Galaxy: abundances - surveys Abstract: We present a new analysis of the LAMOST DR1 survey spectral database performed with the code SP_Ace, which provides the derived stellar parameters Teff, logg, [Fe/H], and [alpha/H] for 1,097,231 stellar objects. We tested the reliability of our results by comparing them to reference results from high spectral resolution surveys. The expected errors can be summarized as ∼120K in Teff, ∼0.2 in logg, ∼0.15dex in [Fe/H], and ∼0.1dex in [alpha/Fe] for spectra with S/N>40, with some differences between dwarf and giant stars. SP_Ace provides error estimations consistent with the discrepancies observed between derived and reference parameters. Some systematic errors are identified and discussed. The resulting catalog is publicly available at the LAMOST and CDS websites. Description: The catalog contains stellar parameters including effective temperature (Teff), gravity (log g), metallicity [M/H], together with chemical abundances [Fe/H] and [alpha/H], derived with the code SP_Ace. It consists of 2,052,662 spectra, mostly Milky Way stars, from which 1,097,231 have measured parameters. The confidence intervals of the stellar parameters are expressed along with their upper and lower limits. Together with these main parameters we report other auxiliary information such as object designation, RA, DE, and other diagnostics as indicated in the table description. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 259 2052662 Stellar parameters and chemical abundances for the SP_Ace-LAMOST DR1 catalog
See also: V/146 : LAMOST DR1 catalogs (Luo+, 2015) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 9 I9 --- ObsID Identification number of the spectrum 11- 29 A19 --- Name Object designation ( 31- 41 F11.7 deg RAdeg Right ascension (J2000.0) 43- 52 F10.7 deg DEdeg Declination (J2000.0) 54- 63 A10 --- Obs.Date Date of observation (YYYY-MM-DD) 65- 69 I5 d LMJD Local modified julian day 71- 90 A20 --- PlanId Plan ID in use 92- 93 I2 --- spId Spectrograph ID 95- 97 I3 --- FiberID Fiber ID 99-104 F6.1 km/s RVb ? Radial velocity correction of the blue part of the spectrum 106-111 F6.1 km/s RVr ? Radial velocity correction of the red part of the spectrum 113-116 F4.1 0.1nm FWHMb ? Full-Width-Half-Maximum of the blue part of the spectrum 118-121 F4.1 0.1nm FWHMr ? Full-Width-Half-Maximum of the red part of the spectrum 123-127 F5.1 --- S/N ? Signal-to-Noise ratio computed by SP_Ace 129-132 I4 K Teff ? Effective temperature 134-137 I4 K b_Teff ? Effective temperature lower limit 139-142 I4 K B_Teff ? Effective temperature upper limit 144-146 F3.1 [cm/s2] logg ? Log gravity 148-150 F3.1 [cm/s2] b_logg ? Log gravity lower limit 152-154 F3.1 [cm/s2] B_logg ? Log gravity upper limit 156-160 F5.2 [-] [M/H] ? Nominal metallicity of the atmosphere model 162-166 F5.2 [-] b_[M/H] ? Nominal metallicity lower limit 168-172 F5.2 [-] B_[M/H] ? Nominal metallicity upper limit 174-178 F5.2 [-] [Fe/H] ? Iron abundance (1) 180-184 F5.2 [-] b_[Fe/H] ? Iron abundance lower limit 186-190 F5.2 [-] B_[Fe/H] ? Iron abundance upper limit 192-195 I4 --- o_Fe Number of iron lines measured 197-201 F5.2 [-] [a/H] ? Alpha-elements abundance (2) 203-207 F5.2 [-] b_[a/H] ? Alpha-elements abundance lower limit 209-213 F5.2 [-] B_[a/H] ? Alpha-elements abundance upper limit 215-217 I3 --- o_a Number of alpha-elements lines measured 219 I1 --- Flag Spectra flag (3) 221-227 A7 --- Class LAMOST classification of the object 229-242 F14.11 --- z ? Redshift (from the LAMOST pipeline) 244-259 F16.11 --- e_z []? Redshift error (from the LAMOST pipeline)
Note (1): we call "iron abundance" the abundance of all non-alpha elements as though they were one single element (see section 3.1 of the paper). Among these elements, iron is the main driver of this parameter due to the preponderance of iron lines. Note (2): the alpha-elements abundance expresses the abundance of Mg, Si, Ca, and Ti, measured as though they were one single element (see section 3.1 of the paper). Note (3): the parameters of spectra with flag=0 must be rejected or treated with extreme caution (see section 3.3 of the paper).
Acknowledgements: Corrado Boeche, corrado(at)
(End) Patricia Vannier [CDS] 09-Apr-2018
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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